Re: [off-topic] Re: Kenwood/Hi-Val True-X 40x CDROM drive.

Mike A. Harris (mharris@ican.net)
Tue, 4 May 1999 05:39:35 -0400 (EDT)

On Tue, 4 May 1999, M.Brands wrote:

>> >I've given up on hdparm. With my generic IDE disk, I get 8 MB/sec, and
>> >about 22 MB/sec if I read from the cache.
>>
>> I get:
>>
>> 2 root@red:/# hdparm -tT /dev/hd[ab]
>>
>> /dev/hda:
>> Timing buffer-cache reads: 64 MB in 1.69 seconds =37.87 MB/sec
>> Timing buffered disk reads: 32 MB in 3.29 seconds = 9.73 MB/sec
>>
>> /dev/hdb:
>> Timing buffer-cache reads: 64 MB in 1.67 seconds =38.32 MB/sec
>> Timing buffered disk reads: 32 MB in 5.01 seconds = 6.39 MB/sec
>>
>> >With my 7200 rpm SCSI disks (OK, SCSI-2, not SCSI-3, but
>> >still...), I get between 1.8 and 3.5 MB/sec (depending on wind
>> >direction, it seems) reading the disk, and 25 to 33 MB/sec
>> >reading the cache (which presumably means it's not the
>> >controller being slower than IDE).
>>
>> My hdparm results seem very indicative of actual transfer rates
>> for IDE disks.
>
>Hmm, now I'm a bit confused. I just tested my disks again and the results
>I'm getting now seem to be ok. (I did the other tests a few days ago.) I
>now get:
>
>/dev/hda: (Maxtor 90845D4)
> Timing buffer-cache reads: 64 MB in 0.89 seconds =71.91 MB/sec
> Timing buffered disk reads: 32 MB in 2.17 seconds =14.75 MB/sec
>
>/dev/hdb: (Seagate ST31722A)
> Timing buffer-cache reads: 64 MB in 0.88 seconds =72.73 MB/sec
> Timing buffered disk reads: 32 MB in 5.53 seconds = 5.79 MB/sec
>
>/dev/hdc: (Maxtor 90845D4)
> Timing buffer-cache reads: 64 MB in 0.87 seconds =73.56 MB/sec
> Timing buffered disk reads: 32 MB in 2.17 seconds =14.75 MB/sec
>
>/dev/md0: (hda & hdc in RAID0 config)
> Timing buffer-cache reads: 64 MB in 0.88 seconds =72.73 MB/sec
> Timing buffered disk reads: 32 MB in 1.62 seconds =19.75 MB/sec
>
>/dev/sda: (external zipdrive)
> Timing buffer-cache reads: 64 MB in 0.92 seconds =69.57 MB/sec
> Timing buffered disk reads: 32 MB in 38.05 seconds = 0.84 MB/sec

It is important when running benchmark tests such as this to not
have any processes running on the machine (idle machine). Also,
run the tests several times to ensure the data is constant.

>Also, I find it a bit odd you CAN test IDE CD-ROMS, but not SCSI ones.

I can test IDE hard disks, and IDE/ATAPI CDROM's, but I can't
test ATAPI CDROMS while the ide-scsi ATAPI-SCSI-EMULATION driver
is being used on my IDE/ATAPI CDROMS. Other things fail too on
the ide-scsi driver...

--
Mike A. Harris                   Linux advocate      GNU advocate
Computer Consultant                          Open Source advocate  


The DVORAK keyboard layout RULES!  I memorized it in 45 minutes
and I don't think I'm ever going back to QWERTY!




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